1. Field of the Invention
This application is directed to an identification symbol which can be used on items to be identified and, more particularly, to a symbol that includes an orientation border and a method for recognizing and decoding the information represented by the symbol.
2. Description of the Related Art
Conventional identification symbols include circular or polar symbols and bar code symbols. Bar code symbols consist of various width bars arranged in a linear orientation. To determine the meaning of a bar code symbol, the symbol must be scanned in a direction substantially parallel with the linear arrangement of the bars. That is, the bar code symbols have a preferred scanning direction and the scanning device must be positioned to scan in the preferred direction. Because the symbol must be properly oriented for scanning, the symbol must be pre-oriented by the symbol identification system user or the scanning apparatus must be capable of scanning in many different directions. Many bar code scanning systems for bar codes on packages and other objects require a quiet zone (a zone of no data lines) in front of the bar code and behind the bar code in the preferred scanning direction. The quiet zone is designed to define an area in which no printing on the package is allowed because printing within the quite zone will render the bar code unreadable. The exterior of the quiet zone constitutes a printing boundary and, on some packages, is defined by a line that can run all the way around the bar code. This line carries or imprints no timing or orientation information and is merely used to define the printing boundary of the symbol. The boundary line is not part of the symbol. The circular identification symbols also suffer from the scanning orientation problem and must be scanned in one direction although the symbol can be in any orientation. Because of the need to scan the conventional symbols in a preferred direction and because many items that include such symbols are randomly oriented when they arrive at a symbol reader, a need has arisen for a symbol that contains high data density and which can be oriented in any direction and still be cost effectively machine readable.